Ring cutters have been known for many years in the art of milling and, in particular, gear cutting. U.S. Pat. No. 2,129,077 to Wildhaber discloses a cutter comprising a continuous, closed ring mounted to the nose of a cutter spindle. The ring cutter is stated to be very stiff due to the continuous ring and accurately concentric due to the fact that the teeth are ground in place.
It can be seen that producing the teeth of a ring cutter in place is advantageous since this approach eliminates the need to assemble a cutter by placing and positioning individual blades in a cutter head, such as illustrated by U.S. Pat. No. 4,575,286 to Blakesley, or, mounting blades about the periphery of a cutter head, such as illustrated by U.S. Pat. Nos. 2,994,943 to Carlsen et al. or 3,138,996 to Dammert et al.
However, mounting a cutter ring on a spindle as disclosed by previously mentioned U.S. Pat. No. 2,129,077 or mounting a cutter ring on a cutter head as disclosed by U.S. Pat. Nos. 2,828,672 to McMullen or 4,204,787 to McCray et al. requires a precise fit of the cutter ring base and side mounting surfaces to the mounting surfaces of the spindle or head.
If a cutter ring is not precisely mounted to a cutter head or machine spindle, the cutter ring will not rotate true about the axis of rotation of the machine spindle. This nbn-true rotation, known as run-out, can occur radially and/or axially with respect to the axis of rotation of the cutter head and machine spindle. A cutter ring rotating in this manner will result in imprecisely formed tooth geometry on a workpiece, such as a gear or gear blank.
It is an object of the present invention to provide a rotary ring cutter wherein the cutter ring will be concentric with the axis of rotation of the rotary cutter.
It is another object of the present invention to provide a rotary ring cutter which offers rapid assembly and disassembly as well as repeatable accurate placement of a cutter ring on a cutter head.